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The quick rate of retreat of the Triglav Glacier, which began in the second half of the 20th century, further accelerated throughout the 90s. Due to increasing intensity of ice thinning, outcropping rocks began to emerge in the middle of the glacier, which disintegrated into two parts in 1992. In the 21st century, the glacier has been retreating at a slower rate. The last major recession of the glacier was registered after the above average hot summer of 2003. The process stalled in years with above-average snowfall in late spring.


This indicator shows changes in the surface area and volume of the Triglav glacier in the period 1992–2016 (volume measurements are periodical) and the average decade temperature of the melting season (May–October) at Kredarica in the period 1961–2016. The cumulative specific mass balance of selected European glaciers in the period 1946 – 2014 and in 2015 is presented as well. The measured surface area of the Triglav glacier includes glacier ice as well as snow directly above or adjacent to the glacier unless indicated otherwise. Glacier ice is entirely exposed only on rare occasions and only exceptionally for the period of several consecutive years.

Mass balance is the difference between accumulation and ablation of ice or snow covering the glacier. Due to variable density of snow and ice, it is expressed in mm of water equivalent. Specific mass balance means an average value per unit of surface area.

A glacier is a perennial mass of ice on the Earth’s surface that moves downslope under its own weight in response to gravitational force. A glacier forms above the snow line in locations where the mass accumulation of snow and ice exceeds ablation over many years. The snow is gradually transformed into glacier ice, which moves downslope reaching below the snow line until the glacier ice disappears due to prevailing ablation. The key factors of ablation are: sun radiation (intensity, duration), air temperature, precipitation and wind (Gabrovec, Zakšek, 2007).

Changes in glacier volume and extent are an illustrative indicator of climate change. During the last decade, the trend of rapid glacier retreat has been characteristic of all Alpine glaciers. In Slovenia, there are two glaciers: the Triglav glacier and the Skuta glacier. Due to their extreme south-eastern position and low altitude, both are exceptionally sensitive to climate changes. Due to the small size of Slovenian glaciers, their relative retreat in respect to their present extent and volume is greater than in other Alpine glaciers.


Charts

Figure PS05-1: Changes in the Triglav glacier surface area, 1992-2016
Sources: 

Anton Melik Geographical Institute, Slovenian Academy of Sciences and Arts, 2016.

Show data
1992 1995 1999 2003 2005 2007 2008 2009 2010 2011
surface ha 4.3 3 1.1 0.7 1.1 0.6 1.1 2.9 2.5 2.4
2012 2013 2014 2015 2016
surface ha 0.6 2.5 3.6 1.7 1
Figure PS05-2: Changes in the Triglav glacier volume, 1992-2013
Sources: 

Anton Melik Geographical Institute, Slovenian Academy of Sciences and Arts, 2013.

Show data
1992 1999 2005 2008 2013
Volume (1000m3) 400 60 20 10 7.4
Figure PS05-3: Extent of the Triglav glacier, 1850-2012
Sources: 

Gabrovec, M., Hrvatin, M., Komac, B., Ortar, J., Pavšek, M., Topole, M., Triglav Čekada, M. in Zorn, M., 2014: Triglav glacier, page. 234.

Figure PS05-4: Average temperature of the melting season at Kredarica, 1961-2016
Sources: 

Slovenian Environment Agency, 2016.

Show data
1961-1970 1971-1980 1981-1990 1991-2000 2001-2010 2011-2016
Average temperature of the melting season oC 3.3 2.7 3.7 3.8 4.2 4.5
Figure PS05-5: Cumulative specific net mass balance of glaciers, 1946-2015
Sources: 

World Glacier Monitoring Service, 2016.

Show data
1946 1947 1948 1949 1950 1951 1952 1953 1954 1955
Careser (IT) mm w.e.
Gries (CH) mm w.e.
Hintereis (AT) mm w.e. 0 -540 -826 -750
Saint Sorlin (FR) mm w.e.
Sarennes (FR) mm w.e. 0 -2990 -4610 -4410 -6030 -6670 -7220 -6560
Vernagt (AT) mm w.e.
Storglaciaeren (SE) mm w.e. -1130 -3190 -3190 -2290 -3580 -4230 -4390 -5200 -6170 -6330
Nigardsbreen (NO) mm w.e.
Austre Broeggerbreen (NO) mm w.e.
Aalfotbreen (NO) mm w.e.
Hofsjokull N (IS) mm w.e.
Maladeta (ES) mm w.e.
1956 1957 1958 1959 1960 1961 1962 1963 1964 1965
Careser (IT) mm w.e.
Gries (CH) mm w.e. 0 -984 -1164 -1852 -1407
Hintereis (AT) mm w.e. -1025 -1214 -2195 -2958 -3020 -3225 -3921 -4524 -5768 -4843
Saint Sorlin (FR) mm w.e. 0 -360 -330 -1540 -1870 -1760 -2860 -2590 -4240 -3780
Sarennes (FR) mm w.e. -7160 -7680 -8350 -9610 -9490 -9880 -10790 -10600 -12430 -12400
Vernagt (AT) mm w.e. 0 751
Storglaciaeren (SE) mm w.e. -6810 -7130 -7780 -8750 -10360 -11460 -11140 -11330 -10840 -10410
Nigardsbreen (NO) mm w.e. 0 2250 2030 2980 3890
Austre Broeggerbreen (NO) mm w.e.
Aalfotbreen (NO) mm w.e. 0 -1100 -820 -340
Hofsjokull N (IS) mm w.e.
Maladeta (ES) mm w.e.
1966 1967 1968 1969 1970 1971 1972 1973 1974 1975
Careser (IT) mm w.e. 0 -390 -130 -130 -760 -1410 -1010 -2290 -2610 -2440
Gries (CH) mm w.e. -1764 -1735 -1356 -623 -1381 -1908 -1500 -2595 -2773 -2395
Hintereis (AT) mm w.e. -4499 -4479 -4141 -4572 -5124 -5724 -5798 -7027 -6972 -6907
Saint Sorlin (FR) mm w.e. -3080 -3540 -2730 -2290 -2160 -3010 -3250 -4010 -4830 -4550
Sarennes (FR) mm w.e. -11980 -12390 -12050 -12410 -12820 -13920 -14290 -15160 -16760 -16650
Vernagt (AT) mm w.e. 1383 1466 1767 1460 1236 812 949 489 719 890
Storglaciaeren (SE) mm w.e. -10940 -11170 -11270 -12310 -13830 -14020 -15070 -15020 -15360 -14190
Nigardsbreen (NO) mm w.e. 2970 5130 5350 4040 3480 4300 4160 5260 5740 6010
Austre Broeggerbreen (NO) mm w.e. 0 -650 -750 -1680 -2220 -2800 -3110 -3190 -4110 -4420
Aalfotbreen (NO) mm w.e. -1950 -670 280 -1890 -3120 -2180 -2290 -110 920 2130
Hofsjokull N (IS) mm w.e.
Maladeta (ES) mm w.e.
1976 1977 1978 1979 1980 1981 1982 1983 1984 1985
Careser (IT) mm w.e. -2710 -1720 -1640 -1820 -1810 -2650 -4330 -5120 -5710 -6470
Gries (CH) mm w.e. -3416 -2250 -1194 -2079 -1509 -1833 -3137 -3916 -3920 -4446
Hintereis (AT) mm w.e. -7221 -6461 -6050 -6269 -6319 -6492 -7732 -8312 -8280 -8854
Saint Sorlin (FR) mm w.e. -5960 -4630 -3770 -3540 -2630 -2430 -2890 -3030 -2650 -3120
Sarennes (FR) mm w.e. -18720 -17730 -17180 -17290 -16970 -16930 -17030 -17100 -17140 -18350
Vernagt (AT) mm w.e. 940 1292 1580 1624 1764 1709 864 327 347 235
Storglaciaeren (SE) mm w.e. -13920 -13720 -13800 -14010 -15280 -15470 -15210 -14930 -14810 -15530
Nigardsbreen (NO) mm w.e. 6410 5640 5510 6220 5000 5310 4890 5980 6320 6100
Austre Broeggerbreen (NO) mm w.e. -4870 -4980 -5540 -6250 -6770 -7320 -7360 -7630 -8360 -8910
Aalfotbreen (NO) mm w.e. 3660 3100 2590 2460 1850 2070 1940 3540 4860 4300
Hofsjokull N (IS) mm w.e.
Maladeta (ES) mm w.e.
1986 1987 1988 1989 1990 1991 1992 1993 1994 1995
Careser (IT) mm w.e. -7610 -9250 -10260 -11080 -12660 -14390 -15590 -15890 -17630 -18710
Gries (CH) mm w.e. -5393 -6126 -7050 -8121 -10109 -11453 -12578 -13630 -13839 -14117
Hintereis (AT) mm w.e. -9586 -10303 -11248 -11885 -12880 -14205 -15325 -15895 -17005 -17465
Saint Sorlin (FR) mm w.e. -4690 -5080 -4920 -7350 -8510 -9570 -11310 -12280 -12610 -11940
Sarennes (FR) mm w.e. -20140 -21060 -21750 -24340 -26480 -27840 -29150 -30350 -30980 -30220
Vernagt (AT) mm w.e. -573 -863 -1360 -1672 -2240 -3319 -4177 -4649 -5677 -6075
Storglaciaeren (SE) mm w.e. -15590 -15110 -15950 -14710 -14120 -13950 -13070 -12070 -12440 -11740
Nigardsbreen (NO) mm w.e. 6000 7480 6590 10060 11830 12030 13630 15480 16040 17230
Austre Broeggerbreen (NO) mm w.e. -9230 -9010 -9530 -9980 -10640 -10510 -10610 -11640 -11800 -12580
Aalfotbreen (NO) mm w.e. 3890 5960 3480 6410 8200 8990 11280 13460 14240 15440
Hofsjokull N (IS) mm w.e. 0 -740 -160 -760 -2170 -1110 -200 -120 -800
Maladeta (ES) mm w.e. 0 -327 -359 -8 -651
1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Careser (IT) mm w.e. -20030 -20960 -23200 -25000 -26610 -26860 -28009 -31326 -32888 -34893
Gries (CH) mm w.e. -14634 -15702 -17755 -18319 -19304 -19533 -20523 -23234 -24380 -25892
Hintereis (AT) mm w.e. -18292 -18883 -20115 -20976 -21609 -21782 -22429 -24243 -24910 -25971
Saint Sorlin (FR) mm w.e. -12450 -12610 -14830 -15870 -17110 -16950 -18640 -21590 -24040 -26540
Sarennes (FR) mm w.e. -30220 -30650 -32990 -34050 -35584 -35194 -37514 -40654 -43474 -46754
Vernagt (AT) mm w.e. -6488 -6975 -7978 -8086 -8373 -8597 -8863 -10996 -11403 -11926
Storglaciaeren (SE) mm w.e. -12130 -12760 -13280 -13460 -12880 -13580 -14410 -15450 -15570 -15640
Nigardsbreen (NO) mm w.e. 16820 17290 18260 18430 20150 19931 19043 17884 17841 18939
Austre Broeggerbreen (NO) mm w.e. -12750 -13460 -14320 -14680 -14700 -15180 -15760 -16660 -17780 -18780
Aalfotbreen (NO) mm w.e. 13560 13640 13750 13810 15800 13707 12177 9675 9575 10243
Hofsjokull N (IS) mm w.e. -1580 -2630 -3310 -3560 -4900 -5480 -6480 -7460 -8820 -9250
Maladeta (ES) mm w.e. -444 68 -887 -1651 -2551 -2049 -2860 -3962 -5478 -6957
2006 2007 2008 2009 2010 2011 2012 2013 2014 2015
Careser (IT) mm w.e. -36986 -39731 -41582 -42919 -43858 -45780 -45780 -48240 -49279 -49410
Gries (CH) mm w.e. -27887 -29360 -30961 -31844 -33151 -35301 -35301 -37341 -37883 -40113
Hintereis (AT) mm w.e. -27487 -29285 -30519 -31701 -32521 -33940 -33940 -35501 -36011 -36133
Saint Sorlin (FR) mm w.e. -27980 -30230 -32040 -34690 -35690 -38710 -38710 -40840 -41796 -43136
Sarennes (FR) mm w.e. -49134 -51654 -53994 -57894 -59424 -63577 -63577 -66267 -67637 -69547
Vernagt (AT) mm w.e. -12808 -13774 -14617 -15576 -16256 -17211 -17211 -18366 -18791 -18935
Storglaciaeren (SE) mm w.e. -17360 -16950 -16370 -16900 -17590 -18650 -18650 -17970 -19380 -20270
Nigardsbreen (NO) mm w.e. 17540 18587 19687 19917 19117 18286 18286 19560 19328 18985
Austre Broeggerbreen (NO) mm w.e. -19510 -19967 -20097 -20350 -20790 -21794 -21794 -21969 -23019 -23009
Aalfotbreen (NO) mm w.e. 7053 8323 9003 8853 7013 6168 6168 7529 6625 4972
Hofsjokull N (IS) mm w.e. -9760 -10150 -10720 -11070 -13470 -13790 -13790 -14250 -14610 -15560
Maladeta (ES) mm w.e. -8744 -9691 -9729 -11143 -10884 -12388 -12388 -14859 -14469 -14391

Goals

  • to adapt to climate change and to reduce potential negative impacts (extreme/exceptional weather events);
  • to limit the rise of temperatures below 2oC compared to pre-industrial levels (Paris Agreement)
  • to adopt urgent measures to combat climate change and its consequences (2030 Agenda for Sustainable Development);
  • to promote adaptation to climate change in key vulnerable sectors (EU strategy on adaptation to climate change);
  • to encourage Member States to adopt measures for protection against climate change (EU strategy on adaptation to climate change).

 


Similar oscillations within the last 400 years are typical of all Alpine glaciers. Following their peak at the beginning of the 17th century, glaciers remained at their maximum extent for the next 250 years, undergoing relatively insignificant changes. Most glaciers in the eastern Alps reached their second peak between 1770 and 1780, and in the mid-19th century. However, the post-1920 period records a continuous retreat of glaciers; the only variations occurring between individual years and decades were those concerning the rate of glacier retreat.

The melting of the Triglav glacier intensified during the 1990’s. The increasingly rapid thinning of the glacier ice caused individual rock formations to appear in the middle of the glacier, finally cutting it into two completely separate parts in 1992. The melting and disintegration of the Triglav glacier is still continuing, with occasional halts in the process occurring in years with exceptionally high snow cover during late spring. This occurred e.g. in 2004, when, at the beginning of July, snow measurement rods below the glacier revealed more than 2 m of snow. The snow cover remained in place until the end of the ablation season, so the glacier remained covered by snow and the measurements made no sense. The snow remained at the bottom of the glacier until the end of summer 2005, which is why the glacier’s surface area in this year was greater than in 2003. The smallest glacier area before 2016 was recorded in 2007, when it measured 0.6 ha. At the end of the melting season in 2008, the glacier was still mainly covered with snow from the previous winter season, and its measured surface area therefore amounted to 1.1 ha. The most significant glacier recovery occurred in 2009 and 2014, mostly thanks to above-average snow cover during two consecutive winters of 2008/09–2009/10 and 20012/13–2013/14, during which numerous avalanches were triggered as well. At the end of the melting season in 2010, when most of the glacier was covered with thick layers of old snow, the glacier’s surface area was 2.5 hectares. It was similar at the end of the melting season in 2014, when it measured 3.6 hectares.

In September 2013, georadar measurements were carried out (13 cross sections with a length of 40–82 m in the NNE–SSW direction). They revealed that the surface area of glacier ice was 0.38 hectares (2.5 hectares including the snow on top of and adjacent to the glacier), while its volume amounted to 7,400 m3. The greatest thickness in some places was 5 m and the average thickness was 1.95 m. Including the snow on top of and adjacent to the glacier, the greatest thickness was 8 metres, while the average thickness was no more than 3 metres.

The trend of ice build-up stopped during the melting season in 2015, when the glacier's surface area was reduced by more than 50%, to 1.7 hectares. Its thickness, and consequently its volume, was reduced even more (several metres in places). All of the firn that accumulated between 2005 and 2014 disappeared due to intensive melting. By the end of the melting season in 2016, only a few small patches of firn were preserved in the upper part of the glacier. It is impossible to precisely determine when the glacier will disappear, as it is not possible to precisely predict the course of local climate change in the Triglav glacier area that will result from global climate change. If unfavourable climate conditions for the glacier's growth continue in future years, it is highly probable that the glacier will further disintegrate into a larger number of smaller parts and gradually disappear.

When measurements began in the mid-1950s, the melting period was slightly shorter than the accumulation period, while in recent decades it has usually been the opposite. The glacier balance is very fragile, as current temperature conditions and other factors threaten the preservation of the Triglav glacier. If atmosphere warming continues at the rate witnessed in the last two decades, the glacier will eventually disappear. More snowfall in the area of the glacier, which is a possible result of global climate change, will only temporarily delay the glacier's gradual disappearance.

The average temperature of the melting season (May–October) was notably above the long-term average in the second half of the 1970s (0.3°C) and the second half of the 1980s (0.4°C). An exceptional temperature rise (0.7°C) occurred at the break of the 21st century, after which the average temperature of the melting season remained relatively stable. With regard to the reference period 1961–1990, the temperature of the melting season in 2016 was 0.8°C above the long-term average. A similar trend of warming and, consequently, retreating glaciers, is taking place throughout the Alps.

 

 

 



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